


Into the Darkness

by drunkdragon



Category: Demon's Souls, RWBY
Genre: Alternate Universe - Medieval, Canon-Typical Violence, F/M, Fantasy, Mercury as Maiden in Black, Yang as Slayer of Demons, other characters and ships as they appear, rough adaptation of the video game's mechanics
Language: English
Status: Completed
Published: 2018-03-12
Updated: 2018-03-26
Packaged: 2019-03-30 07:42:48
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 3,817
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13946877
Author URL: https://archiveofourown.org/users/drunkdragon/pseuds/drunkdragon
Summary: But perhaps this is your calling. When you first told us all and Father left the room, I feared he would be taking out the switch. Instead, he returned with the sword he always claimed was his best creation - the one he refused to replicate - and gave it to you. Even a month after, his words still ring in my ears, that upon your birth he knew you would seek danger, just like your true mother.I can see no point in dissuading you any further. All I can offer you is this letter. And while I know you are of little faith, I nonetheless pray for your safe return. Umbasa.





	1. Chapter 1

“Well done, Slayer of Demons. Perhaps you are the one that we have waited for.”

It was him. Not long after the trip into the fog where she was struck down, body crushed by the axe of a heavy demon, a voice called out to her, one that lulled her into what those around her called the Nexus. For that moment she saw only his feet, and then her world returned to darkness. And when she came to, he was nowhere in sight.

But now with her full body again, muscle and bone aching and screaming from the thrashing she had just received, he was there. She had been victorious against that very same demon, but the soothing balms were beginning to wear off. All of the pain was beginning to catch up to her now that she had regained her full self. It was a miracle that she still found it in herself to stand, and even that fell short - with a step, she stumbled and crashed to the ground. His voice was remained silent as she gathered her breath. Finally, though, it became bearable and she looked up at him.

Gray and long-hardened layers of wax covered his eyes. It was the first thing Yang noticed on his young face. Had he not first summoned her to this place, she might have ventured to guess that perhaps this man could have wandered in the streets of her hometown. His clothes, however, were of black cloth wound around him and draped by an equally dark cape. A stark contrast against the weaves of drawing darkness, however, was his silver hair, messy and tousled.

In his hand was a long, thin pole, the tip of it lit in small blue flames. As he cautiously stepped down the stairs, the bottom of it gently scraped across the edges and sides, guiding his feet to the bottom and to her. Finally, though, his feet came to a rest at her front, his head failing to tilt and meet her gaze.

The denizens of the Nexus had given mixed thoughts about him. One person felt pity, for he was blinded and ever wandered the halls of the Nexus. Another said that he was the son of the a demon and wielded immeasurable power. Still others warned her not to grow attached to the strength he provided. But as her body ached in pain, she was reminded of the battle that she hardly survived.

“Slayer of Demons,” perhaps that was his name for her, for they had never been fully introduced. “You seem to be troubled.”

“It’s-” she coughed, the pain echoing through her body once again, “It’s Yang.”

“Then… Yang,” he slowly spoke. Lowering his body until he was upon one knee, the bottom of his pole gently moved towards her until it stopped softly at her side. “Forgive me. I must find you before I can tend to you, after all.”

Then one of his hands detached from the pole before falling onto Yang’s leg. Even through the armor, she felt a chill course over her body. But what came afterward was relief. Her body ceased its wailing and breathing became easier. His fingers left her leg before searching to her right, falling onto the gauntlets on her hands. Then they traced up to her shoulder before sidling at her cheek, gently parting the curtains of her blonde hair.

“There is much strength in you, Yang,” his voice felt empowering, just like it was when she first heard him. “There must be, for you have felled a great demon after all. But there will be more - some far greater than the one you have defeated, others crafty and hidden. You must become stronger, and I will bring you there.” A pause. “Do you wish for that?

It was easy to remain here and wish to forget. It was warm, soft and inviting. After so much wandering through the ramparts and fighting through men who had long gone mad, she wanted to rest, to shed this armor and draw respite from the Nexus.

But there was more work to be done. She could not rest here - not until her homeland was free of the accursed fog. “Yes. Please strengthen me.”

There was a small nod. His hand pressed only a breath harder against her cheek. “Go on then. Touch the demon inside me so that you might be strengthened.”

She leaned into his palm and let his power wash over her.

_ Soul of the mind, key to life’s aether _

_ Soul of the lost, withdrawn from its vessel _

_ Let strength be granted so that the world might be mended _

_ So that the world might be mended _


	2. Chapter 2

_ You and Father have never been one for faith. I’ve questioned Mother many a time how she ever found it in her to love him in spite of his worldly values, and I’ve been met only with shrugs and a quiet and shaken head. ‘Perhaps it was my calling. He was far worse off when I first met him than he is today,’ was the most I have ever been given. It’s confounded me time and time again that she would enter into a relationship so openly with a man who already had a child with another. But as I pen this letter, I see more and more truth in those words. _

_ I do not understand your desire, to see the mysteries enshrouded by the fog. None have returned from it, and we can only assume that those who have gone before you are no longer among the living, twisted and consumed by the demons within. _

_ But perhaps this is your calling. When you first told us all and Father left the room, I feared he would be taking out the switch. Instead, he returned with the sword he always claimed was his best creation - the one he refused to replicate - and gave it to you. Even a month after, his words still ring in my ears, that upon your birth he knew you would seek danger, just like your true mother. _

_ I can see no point in dissuading you any further. All I can offer you is this letter. And while I know you are of little faith, I nonetheless pray for your safe return. Umbasa. _

_ With love, Ruby _

* * *

After Yang’s soul reclaimed the form of her body, the self no longer ethereal, there was always pain. Be it arrows, burns, or cuts from a sword, it came in a wave that crushed her. Perhaps it was the fact that her body had shape again and was no longer just a shimmering, translucent mass in the shape of herself that could only imitate the sensation of pain. Where they were previously dulled, they would now ache in a way that caused her muffled sobs to echo across the desolate wings.

She always did her best to hide herself away in the far and sequestered corners of the Nexus, away from the eyes of others fortunate enough to be trapped in the dark walls of the structure.

After the pain subsided, there was always hunger. But it was strange, however. One did not need to eat in this place, or even outside in the world around her. Hunger came and went, but her sword did not grow heavy. Her steps did not become uneasy and her body did not grow faint. She had lost track of when she had last chosen to eat. It was soothing, after all, to have something in her stomach that wasn’t bitter moongrass.

But after an unknown time, fighting through hordes of demons, the herbs were all Yang had left. As a trained soldier, she had a ravenous, lamentable hunger. Whatever hard breads and preserved fruits and meats she had were gone in what must have been a week.

They would have to do, though. Anything to fill her stomach, to stop the gnawing within her. Rising from the ground, she pushed herself up to her knees and kicked out her legs. The metal of her armor clicked against the stone as her back came to rest against the wall. With dread, her fingers threaded to her side, going into the pouch and pulling out the small herb. A heavy sigh.

A gentle scraping, one that she found herself growing accustomed to, pierced her ears. “Ah, so you are over here.” Eyes darting to the voice, Yang saw that Mercury had come to pay her a visit. “You can be such a pain when you wish to, you know.”

Any other time, perhaps she would have said something in return. As…  _ gracious _ as he was to give her power, there was still a level of wariness in her interactions with him. With the mixed rumors about him, there was simply no clear choice in the end. And as she learned through her constant battles against demons and madmen, a grain of caution went far.

But this time, she found herself unable to speak. In one hand was his black pole, with their soft blue flames gently flickering from the tips with his soft steps. His other, however, held a plain white plate, its color contrasting against the sucking black of the cloth on his back and body.

“Is-” she gulped, “Are those-”

“Pancakes,” a quick reply as his body slowly turned to face her direction. Step after step, guided by the scraping tip, he stopped only when it softly collided with her shin. “There isn’t much food in the Nexus - no need for it, after all. But the smithy was feeling particularly kind and appreciative of your efforts and wanted to offer you a small gift.”

How the woman could have been even more appreciative than she already said she was remained a mystery. Never had Yang run into a woman more bubbly and effervescent than Nora. But her eyes remained glued on the plate that he set down in front of her. There weren’t many on the plate, and they were smaller than what her mother would serve her. No syrup, no butter, nor anything else to accompany it. But the steam coming from the top told her that it was fresh and hot.

“Well, go on,” He smiled. “Eat.”

The gnawing called to her, and she all but lunged for it. She took a second bite before she even finished downing the first. Soon the plate was empty, and she leaned back. The feeling was still there, but the pit of her stomach was much less stark in comparison to before. She looked up to see that he was still there.

She was a soldier, Yang reminded herself. She had killed bandits before coming to this accursed land, and ate just as any other soldier ate. But that was different. That was among comrades and people who were just as hungry as she was, or her family. Here she was under his scrutiny, as blind as he was, and it was different.

But as she looked up, she saw that his head was tilted downward at her. If it had not been for the wax covering his eyes, Mercury would have been staring right into hers. But that should have been impossible. He should not have been able to-

“You can see.”

He smiled a little, perhaps almost sheepishly. “Not in the way that you currently fear. But yes. I can see some things.”

Damn her choice for hiding in this corner - there was nowhere to flee to. “So the rumors are true then. You are a demon.”

“Indeed. I am the son of one. But I have been called to this place and have given up my old ways. You’ve nothing to fear from me.”

“Yet you help me.” She tried not to reach for her sword. “Why?”

His shoulders rose and fell. “It is what I have been bound to do, however long it may take for one such as you to mend this place.” His smile grew again, his stare unwavering from her eyes. “But perhaps I am right to believe that you are the one.” He knelt down, gently laying a hand upon her right wrist, her sword arm. “There appears to be something inside of you.” He softly turned it back and forth in his fingers as he stared at it, the metal armor softly tapping against each other. “Something I had missed previously, for it was so miniscule when we first met. But as I fed and grew your power, I see it more and more now.”

She gulped. His face was so close now. Behind the trickles of soft silver hair, she could see the individual rivulets of wax that were applied and reapplied from time unknown. And he was young. Perhaps just as young as she was. He had the formings of a defined chin, and she breathed deep. “What do you see?”

At once his smile paused and faded. The flesh of his cheeks stretched with the frown of his lips. “It is not so easy,” he licked his lips. “For some time I wondered how to share with you my results, for I fear that you will not like the answer.”

“Tell me.”

“.... I see the makings of a demon with you, ingrained in your soul for far longer than you have been at the Nexus.” His fingers let go of hers, tracing and stopping up to the shoulder. “That is something my powers cannot impart you with.”

Her lips pursed, fumbling for words as the heat on her face went away. “What do you mean? Are you saying I was born with a demon residing in me?”

The heat of his fingers lingered on her for a little longer before Mercury leaned away, resting his weight against his knees. “You have lasted longer than anyone else, Yang, even those that I have empowered. None have been as successful as you in the slaying of demons, and they cannot withstand the madness that comes with losing their body for too long. The souls of those you have defeated nourish you in a way they do not for others.”

“Perhaps you really are the one I have waited for.”

She wanted to scream. Did he even understand what he was saying? Of who he was accusing? The demons were wretched and foul beasts. No ability to feel remorse. No desire but to further their own. Her mother and father were kind people. They could not house the vileness of such monsters.

“Your name,” she gulped it down. “I know you as Mercury, but that is all I have heard from the others. What is your full name.”

His body tilted forward just a little, as if doing his best to imitate a bow from his kneeling position. “I am Mercury of the Blackness.”

“Then, Mercury of the Blackness, I apologize but I must ask that you leave me be.”


	3. Chapter 3

She wanted to believe she was strong. There was no other option, after all. To believe that she was weak, to believe that she couldn’t defeat the perils within the fogged land was failure.

Yang did not leave her family only to fail. Her father’s sword was too heavy in her hands and her sister’s words were too heavy in her heart. And all the countless others of the world were relying on her, weighing down upon her shoulders. She would not lose to the madness.

She had lost count of how many times she had died. How many times she had been pushed off a cliffside, impaled, her hand and head cut off, or a slow death by poison. The blows would be dulled, bearable enough to pick up the blade and try again. But she knew that the moment her body returned, her rotting corpse given flesh anew, that’s when the true pain would come. Until then, though, each monster felled made her stronger, even without the help of Mercury.

And here, in the crevice of a deep valley that stank of foul water and death and inhabited by the outcasts and pariahs of society, the time was nigh. In its deepest point, where the sun was too cowardly to shine into, resided its strongest demon. All other humans in the area, with their deformities and other wounds, served her with fervid abandon and ferried her soul after soul to nourish her.

Yang had thought it to be a horrid temptress - a demon that promised everything and gave nothing in return, to offer succor and sow discord among them. But as she rounded the final corner, stepping over the heavily armored body of her guard, she was greeted with a small woman in the white clothes of the church seated upon rocks. From her fingers, ever clasped in prayer, came a small ever-trickling stream of blood. It fed down her white dress and to the muddied, plague-ridden waters that soiled her hem.

“So,” she did not look up at Yang, her straight and short blonde locks hidden behind the white hood. “You have come to end their sanctuary. And you have consumed the soul of my dear guard.”

She said nothing, only watching the woman shake and tremble in her spot. Her back hunched forward, “I sought only to offer peace to this forsaken space, that its denizens might know rest and be accepted. Wielding the power of a demon to do so has not changed that.”

_ Don’t think. Be wary of deception. She cannot possibly save this place alone. _

“O Slayer of Demons, will you say nothing?”

The woman before her was a demon, the strongest in this wretched land. She was trying to deceive her.

_ She has abandoned many to save the few. _

The woman’s gaze turned upward, towards the crack in the earth that revealed the sky. “But I am not one for violence.” Her fingers tightened. “Do as you like. Take your precious demon soul.”

_ She feeds the growing fog. _

Yang stepped forward, blade in hand. “I will make it quick then.”

_ Kill her and become stronger. _

It wasn’t the first archdemon she had slain, after all.

* * *

Strangely, there was no searing of pain across her body when her form returned. Only power, euphoric in its nature. It was a pleasant kind of warm, like a dying coal bedded by ashes. Not hot enough to burn, but just waiting to ignite. It was like a hand had come around to protect her.

“She’s turning! She’s turning! Someone stop her!”

And there was more to gather. More souls to pool and strengthen herself with.

“Nora, bring Mercury here!”

But a demon resided here, a powerful one, and she wanted to kill it. Her body screamed for it. And as she sensed its presence draw closer, that ember-y feeling began to burn. 

“There is no need. I am here.”

The edges of her vision began to swim, turning orange and red. And when he came into view, everything became hot. Her fingers began to glow, the grip of her blade melting in her hands like snow. She didn’t even need her sword, didn’t need the gauntlets, and she threw them all to the ground. Her bare fists were enough.

_ Him! This is the one! _

Her screech shook the walls and Yang lunged at him. His staff clattered to the ground, the blue flames snuffing themselves the moment it left his hands. Their bodies rolled, and in the tussle she climbed onto his still form.

Wax might have blocked his eyes, but she knew he was watching her. Watching in the only way that he could. How else did he always seem to know when she returned, and when she was skulking her pain away in a corner?

_ Kill him! Take his soul and everything else! _

The first hit was at his temple. The second at this jaw. The rest were merciless. And yet with each blow, the shape of his head remained unchanged.

_ Kill him!  _

Every strike was heavier than the last, and yet nothing. Even when she tried to dig her fingers into his skin, letting the heat singe and burn away, his body was unharmed.

A frustrated growl left her throat and she paused. Mercury’s head turned to face her. “Have you come to your senses, Yang?”

She saw the crack in the wax. It hadn’t melted, but it was beginning to break. Her left hand went and pushed his head onto the ground, holding him still as her other reared back.

_ I want his soul! KILL HIM! _

With a roar that rivaled beasts and dragons, her fist came down onto the wax. The stone tile beneath her splintered and gave way to her force. Then another, and another. The wax was giving away, and she drove home one last strike.

“All done now?”

What was beneath it terrified her. There was flesh. The skin from the bridge of his nose flowed naturally and gave way to an eyelid. But as it opened, there was nothing. She had thought that it was just his eye that were black, but there was no reflection of light. Just darkness, a sucking void that was the inside of his body, one that fed upon the power of a thousand other demon slayers and more.

_ Kill him before he kills you! Kill him before he takes your soul! _

Her hand pulled back again, but this time his own palm reached out and stopped it in its place. And though her hands were hot, his hand was freezing. She reeled back in shock, but his other hand grasped the collar of her armor and easily threw her onto her back.

“The soul arts are not your enemy, Yang. Please, do not be like this. Do not become like those before you.”

She had to flee, but he stood between her and the exit. As he stepped closer, she took a step back, tripping over the steps rising back into the heart of the nexus.

“As the archdemon of this sanctuary, I have waited too long.”

She tried to scramble to her feet, but he was already upon her. Just moments ago she was smashing away at his skull, but now his own hand was holding down her shoulder, cold as ice and biting through the pauldrons. The other rose up, and in his palm was a seam, one that she had never noticed before. It parted in the center, slowly revealing the black center of his body once more.

“I will not let you lose.”

It gently came upon her lips.

_ Monstrous soul, you do not belong here _

_ Loosen your hold, unleash this prisoner _

_ You have no authority in the Nexus _

_ And I banish you to the void within me! _

There was a scream, guttural and loud. It was followed by a sense of quiet, one that Yang hadn’t felt since the fog first appeared all those years ago.

**Notes for the Chapter:**

> In which Yang (almost) gets banished to the shadow realm~


End file.
